The present disclosure relates to subject matter contained in priority Japanese Patent Application No. 2001-71734, filed on Mar. 14, 2001, the contents of which is herein expressly incorporated by reference in its entirety.
1. Field of the Invention
The present invention relates to a compressor with a built-in electric motor suitable for mounting on a mobile structure such as an electric vehicle or a hybrid vehicle, and is used with a battery. The invention also relates to a mobile structure having such a compressor.
2. Description of Related Art
In a vehicle driven only by an engine, a compressor driven by the engine has been used for air-conditioning the vehicle compartment with the compressor being mounted alongside of the engine.
Electric vehicles and hybrid vehicles having both an engine and an electric motor and traveling by use of one of them according to conditions have been practically used for going on public roads. Between the two kinds of vehicles, most of those going on public roads are the hybrid vehicles, and air-conditioning of the vehicle compartment is made by a refrigerating compressor driven by the engine in the same manner as conventional engine-driven vehicles.
It is proposed that the engines of hybrid vehicles should be shut off while they are temporarily stationary at a place such as a traffic light in order to reduce effects of the engine upon the environment. When the proposal is followed with a vehicle where a compressor driven by the engine is used, air-conditioning stops each time when the vehicle stops, causing problem for the driver and passengers in the compartment in summer and winter seasons, and especially in regions with extremely cold or hot climate.
Consequently, an idea of adopting for a compressor driven by an electric motor is conceived. Further, it is natural that, in an electric vehicle, a compressor driven by an electric motor is adopted for conducting air-conditioning. Compressors driven by electric motors include maintenance-free compressors integral with electric motors used for air-conditioning of houses, and it is preferable if such compressors can be used for electric vehicles.
The present inventors made various examinations and studies for finding possibility to use a compressor integral with an electric motor originally designed for air conditioning indoors for electric vehicles or hybrid vehicles. The result showed that a rotating shaft of an electric motor became unstable in position in an axial direction, which caused strong contact, friction, and collision between opposing faces of the rotating shaft and a main-shaft receiving member that receives a main shaft of the rotating shaft, revealing the existence of problems with respect to durability. This is because a compressor for indoor air-conditioning is stored within an outdoor unit and fixedly installed with no consideration made for motions as well as shocks applied from the outside. Vehicles often make sudden start, stop, abrupt acceleration and deceleration, and sharp cornering at high speeds. Also, large inertia force much larger than the magnitude of a preload that is given to the rotating shaft is sometimes applied to the rotating shaft and a rotor of the electric motor unitized with the rotating shaft. When such inertia force acts in the direction opposite to that of the preload, the rotating shaft moves, instantaneously and with large force, together with the rotor toward the main-shaft receiving member, causing strong collision between the opposing faces of the shaft and the receiving member. Also, the opposing faces frequently contact with each other and rub against each other.
An object of the present invention is to provide a compressor with a built-in electric motor, which is constituted such that a rotating shaft of the electric motor of the compressor is made to be stable in an axial direction so as not to cause strong friction and collision between opposing faces of a flange portion of the rotating shaft and a main-shaft receiving member. It is also an object of the invention to provide a mobile structure using the compressor described above.
In order to achieve the above objects, a compressor with a built-in electric motor according to the invention includes an electric motor and a compressing mechanism which is connected to and driven by a rotating shaft of the electric motor, and they are accommodated in a case. In this compressor, a main shaft on the side of the compressing mechanism of the rotating shaft and an auxiliary shaft at the side opposite to the main shaft of the rotating shaft are supported by a radial plain bearing and a rolling bearing so that a predetermined clearance in an axial direction is given to the rotating shaft, a flange portion for aligning the rotating shaft with the compressing mechanism through the contact of the main shaft with a main-shaft receiving member that supports the radial plain bearing, and the rotating shaft is given with preload toward the rolling bearing. The compressor is provided with a prevention member between opposing faces of the flange portion and main-shaft receiving member in order to prevent contact and/or collision of the rotating shaft with the main-shaft receiving member.
As described above, the prevention member is located between the opposing faces of the flange portion of the rotating shaft and the main-shaft receiving member. Consequently, this constitution does not prevent necessary clearance from being provided between the opposing faces, and does not prevent preload toward the rolling bearing from being given to the rotating shaft. Conventional operating performance is therefore guaranteed. When the opposing faces are about to strongly contact with each other to cause friction and collision between them because of large force such as inertia force acting in the direction opposite to that of the preload, such force is prevented by the prevention member between the opposing faces from acting. Thus, the opposing faces do not strongly contact with each other to cause friction and collision between them, so that the deterioration in performance and durability of the compressor is prevented.
While novel features of the invention are set forth in the preceding, the invention, both as to organization and content, can be further understood and appreciated, along with other objects and features thereof, from the following detailed description and examples when taken in conjunction with the attached drawings.